Bronchiolitis obliterans syndrome (BOS), bronchiolitis obliterans organizing pneumonia (BOOP), and other late-onset noninfectious pulmonary complications following allogeneic hematopoietic stem cell transplantation

Diagnosis of Post-Hematopoietic Stem Cell Transplantation Bronchiolitis Obliterans Syndrome in Children: Time for a Rethink?

Hematopoietic stem cell transplantation (HSCT) is undertaken in children with the aim of curing a range of malignant and nonmalignant conditions. Unfortunately, pulmonary complications, especially bronchiolitis obliterans syndrome (BOS), are significant sources of morbidity and mortality post-HSCT. Currently, criteria developed by a National Institutes of Health (NIH) working group are used to diagnose BOS in children post-HSCT. Unfortunately, during the development of a recent American Thoracic Society (ATS) Clinical Practice Guideline on this topic, it became apparent that the NIH criteria have significant limitations in the pediatric population, leading to late diagnosis of BOS. Specific limitations include use of an outdated pulmonary function testing reference equation, a reliance on spirometry, use of a fixed forced expiratory volume in 1 second (FEV1) threshold, focus on obstructive defects defined by FEV1/vital capacity, and failure to acknowledge that BOS and infection can coexist. In this review, we summarize the evidence regarding the limitations of the current criteria. We also suggest potential evidence-based ideas for improving these criteria. Finally, we highlight a new proposed criteria for post-HSCT BOS in children that were developed by the authors of the recently published ATS clinical practice guideline, along with a pathway forward for improving timely diagnosis of BOS in children post-HSCT.

Nuances in the interpretation and utility of donor-derived cell-free DNA in lung transplantation following allogeneic hematopoietic stem cell transplantation - Case report

Respiratory complications following allogeneic HSCT can lead to severe morbidity and mortality. Lung transplantation (LT) is a potential treatment for select patients with late-onset non-infectious pulmonary complications post-HSCT. Donor-derived cell-free DNA (dd-cfDNA) is a noninvasive biomarker for monitoring the health of allografts following LT. However, its utility in a multi-genome setting of LT after HSCT has not yet been clinically validated. Here we describe a case of a 75-year-old, male patient who underwent single-lung transplantation for BOS related to chronic GVHD and presented with persistently elevated dd-cfDNA levels. In a surveillance biopsy, the patient was diagnosed with mild acute cellular rejection at three months. The patient's lung function remained stable, and the reported dd-cfDNA levels decreased after the rejection episode but remained elevated above levels that would be considered quiescent for LT alone. In this unique setting, as 3 different genomes contributed to the dd-cfDNA% reported value, valuable insight was obtained by performing further analysis to separate the specific SNPs to identify the contribution of recipient, lung-donor, and HSCT-donor cfDNA. This study highlights the potential utility of dd-cfDNA in the multi-genome setting of lung transplant post-HSCT, nuances that need to be considered while interpreting the results, and its value in monitoring lung rejection.

Lung infections in immunocompromised children

Pulmonary infection is the leading cause of infectious morbidity and mortality in children with immune defects. We provide a comprehensive review of lung infections in immunocompromised children, with a focus on imaging findings and imaging-based management. We include an overview of the immune defences of the respiratory tract, the aetiologies of immune defects in children, the features of specific infections and important differential diagnoses and describe diagnostic strategies using imaging and non-imaging-based techniques.

Extremely late-onset chronic graft-versus-host disease presenting with bronchiolitis obliterans and pleuroparenchymal fibroelastosis

A 35-year-old woman experienced left back pain after a 2-h flight. She reported coughing and left back pain 1 day later when she presented to our hospital. Chest computed tomography showed pneumothorax of the left lung, bronchiectasis, thickening of the bronchial wall, nodules, and cavity lesions in both lungs. A pulmonary function test revealed obstructive ventilation disorder with normal lung diffusing capacity. She had a history of haematopoietic stem cell transplantation (HSCT) at 2 years and 3 months of age during the second disease remission of acute myeloid leukaemia. She was diagnosed with chronic graft-versus-host disease (cGVHD) presenting with bronchiolitis obliterans (BO) and pleuroparenchymal fibroelastosis (PPFE). To our knowledge, this is the first reported case of BO and PPFE diagnosed more than 30 years after HSCT.

Chronic graft-versus-host disease in pediatric patients: Differences and challenges

Despite the use of high-resolution molecular techniques for tissue typing, chronic graft-versus-host disease (cGVHD) remains a major complication following allogeneic hematopoietic stem cell transplant. cGVHD adversely affects the life-expectancy and quality of life. The latter is particularly important and functionally relevant in pediatric patients who have a longer life-expectancy than adults. Current laboratory evidence suggests that there is not any difference in the pathophysiology of cGVHD between adults and pediatric patients. However, there are some clinical features and complications of the disease that are different in pediatric patients. There are also challenges in the development of new therapeutics for this group of patients. In this review, we will discuss the epidemiology, pathophysiology, clinical features and consequences of the disease, and highlight the differences between pediatric and adult patients. We will examine the current treatment options for pediatric patients with moderate to severe cGVHD and discuss the challenges facing therapeutic development for cGVHD in the pediatric population.

Case report: Irinotecan-induced interstitial lung disease in an advanced colorectal cancer patient resurfacing decades after allogeneic bone marrow transplantation for aplastic anemia; a case report and narrative review of literature

Two mechanisms of drug-induced interstitial lung disease (DILD) have been reported: 1) direct injury of lung epithelial cells and/or endothelial cells in lung capillaries by the drug and/or its metabolites and 2) hypersensitivity reactions. In both mechanisms, immune reactions such as cytokine and T cell activation are involved in DILD. While past and present lung diseases and accumulative lung damage due to smoking and radiation are risk factors for DILD, the association between the immune status of the host and DILD is not well known. Herein, we report a case of advanced colorectal cancer with a history of allogeneic bone marrow transplantation for aplastic anemia more than 30 years prior, in which DILD occurred early after irinotecan-containing chemotherapy. Bone marrow transplantation might be a potential risk factor for DILD.

Clinical characteristics of late-onset interstitial pneumonia after allogeneic hematopoietic stem cell transplantation

Non-infectious pulmonary complications after allogeneic hematopoietic stem cell transplantation (HSCT) remain fatal. In particular, information regarding late-onset interstitial lung disease predominantly including organizing pneumonia and interstitial pneumonia (IP) is limited. A retrospective nationwide survey was conducted using data collected from the Japanese transplant outcome registry database from 2005 to 2010. This study focused on patients (n = 73) with IP diagnosed after day 90 post-HSCT. A total of 69 (94.5%) patients were treated with systemic steroids, and 34 (46.6%) experienced improvement. The presence of chronic graft-versus-host disease at the onset of IP was significantly associated with non-improvement of symptoms (odds ratio [OR] 0.35). At the time of last follow-up (median, 1471 days), 26 patients were alive. Of the 47 deaths, 32 (68%) were due to IP. The 3-year overall survival (OS) and non-relapse mortality (NRM) rates were 38.8% and 51.8%, respectively. In the multivariate analysis, the predictive factors for OS were comorbidities at IP onset (hazard ratio [HR]: 2.19) and performance status (PS) score of 2-4 (HR 2.77). Furthermore, cytomegalovirus reactivation requiring early intervention (HR 2.04), PS score of 2-4 (HR 2.63), and comorbidities at IP onset (HR 2.90) were also significantly associated with increased risk of NRM.

Noninfectious Pulmonary Complications after Hematopoietic Stem Cell Transplantation

Pulmonary complications after hematopoietic stem cell transplantation (HSCT) are important sources of morbidity and mortality. Improvements in infection-related complications have made noninfectious pulmonary complications an increasingly significant driver of transplantation-related mortality. Broadly, these complications can be characterized as either early or late complications, with idiopathic pneumonia syndrome and bronchiolitis obliterans syndrome the most prevalent early and late complications, respectively. Outcomes with historical treatment consisting mainly of corticosteroids are often poor, highlighting the need for a deeper understanding of these complications' underlying disease biology to guide the adoption of novel therapies that are being increasingly used in the modern era.

Interstitial lung diseases after hematopoietic stem cell transplantation: New pattern of lung chronic graft-versus-host disease?

Bronchiolitis obliterans syndrome (BOS) after allogeneic HSCT is the only formally recognized manifestation of lung chronic graft-versus-host disease (GVHD). Other lung complications were reported, including interstitial lung diseases (ILDs). Whether ILDs belong to the spectrum of lung cGVHD remains unknown. We compared characteristics and specific risk factors for both ILD and BOS. Data collected from consecutive patients diagnosed with ILD or BOS from 1981-2019 were analyzed. The strength of the association between patient characteristics and ILD occurrence was measured via odds ratios estimated from univariable logistic models. Multivariable models allowed us to handle potential confounding variables. Overall survival (OS) was estimated using the Kaplan-Meier method. 238 patients were included: 79 with ILD and 159 with BOS. At diagnosis, FEV1 was lower in patients with BOS compared to patients with ILD, while DLCO was lower in ILD. 84% of ILD patients received systemic corticosteroids, leading to improved CT scans and pulmonary function, whereas most BOS patients were treated by inhaled corticosteroids, with lung-function stabilization. In the multivariable analysis, prior thoracic irradiation and absence of prior treatment with prednisone were associated with ILD. OS was similar, even if hematological relapse was more frequent in the ILD group. Both complications occurred mainly in patients with GVHD history.

Patient-reported long-term outcome following allogeneic hematopoietic stem cell transplantation in pediatric chronic myeloid leukemia

Background

Pediatric CML is very rare. Before the introduction of tyrosine kinase inhibitors (TKIs), allogeneic hematopoietic stem cell transplantation (HSCT) from a donor -if available- was the standard cure attempt. Data on the long-term outcome and health-related quality of life (HRQOL) in former pediatric CML patients undergoing HSCT are lacking.

Study question

We investigated long-term survivors' self-reporting to a questionnaire sent out to patients formerly enrolled in pediatric CML-HSCT trials.

Methods

Individuals with CML transplanted at age <18 years were identified from the German Childhood Cancer Registry database. Long-term survivors received a questionnaire based on the SF-36 and FACT-BMT asking them to self-report HRQOL issues. (Ethical vote #541_20 B, Medical Faculty, University of Erlangen-Nürnberg).

Results

111/171 (64.9%) individuals survived HSCT long-term and 86/111 (77.5%) fulfilled all inclusion criteria and received the questionnaire. 37/86 (43%) participants (24 female, 13 male, median age at HSCT 12 years [range 2-18], median age at the time of the survey 29 years [range 18-43]) responded after a median follow-up period of 19 years (range 4-27) after HSCT. 10/37 (27%) participants underwent no regular medical follow-up examinations. Self-reported symptoms like chronic graft-versus-host disease (cGvHD)-associated organ impairments and conditioning regimen consequences could causatively not sharply be separated in each case. Complains comprised hypothyroidism (N=11, 30%), infertility (N=9, 24%), lung problems, dry eyes (each N=7, 19%), skin alterations (N=6, 17%), hair problems (N=4, 11%), and sexual dysfunction (N=3, 9%). 10 (27%) participants experienced 13 CML relapses after a median interval from HSCT of 31 months (range 2-93). Only one patient underwent 2nd SCT after failure of relapse treatment with TKIs. Six secondary malignancies (dysplastic melanocytic nevus and ALL, basal cell carcinoma (N=2), rhabdomyosarcoma, and thyroid carcinoma developed in 5 (13%) participants. As assessed by the SF-36 questionnaire, impaired physical health was mainly associated with cGvHD. The mental component summary score showed that also participants without cGvHD scored significantly lower than the general population. When assessed by the FACT-BMT, participants with cGvHD scored significantly lower while participants without cGvHD scored even 5 points higher than the data from controls. 18 (49%) participants considered the sequelae of HSCT an obstacle to education. Out of the total cohort, N=20 (54%), N=7 (19%), N=5 (14%), and N=4 (11%) participants worked full time, part-time, were unemployed, or had not yet finalized their education, respectively. 20 (54%) participants lived as singles, 8 (22%) lived in a partnership, 6 (16%) were married, and 3 (8%) had been divorced. Four (11%) participants reported a total number of 7 children.

Conclusion

This first assessment of HRQOL in former pediatric patients with CML surviving HSCT for more than two decades demonstrates self-reported satisfactory well-being only in the absence of cGvHD. Research-based on self-reported outcomes sheds light on former patients' perspectives and provides an additional layer of valuable knowledge for pediatric and adult hematologists. Regular follow-up examinations are mandatory helping to avoid that late secondary neoplasias, CML-relapse, and disorders forming the broad range of possible long-term consequences of HSCT are not detected too late.

Long-Term Health Effects of Curative Therapies on Heart, Lungs, and Kidneys for Individuals with Sickle Cell Disease Compared to Those with Hematologic Malignancies

The goal of curing children and adults with sickle cell disease (SCD) is to maximize benefits and minimize intermediate and long-term adverse outcomes so that individuals can live an average life span with a high quality of life. While greater than 2000 individuals with SCD have been treated with curative therapy, systematic studies have not been performed to evaluate the long-term health effects of hematopoietic stem cell transplant (HSCT) in this population. Individuals with SCD suffer progressive heart, lung, and kidney disease prior to curative therapy. In adults, these sequalae are associated with earlier death. In comparison, individuals who undergo HSCT for cancer are heavily pretreated with chemotherapy, resulting in potential acute and chronic heart, lung, and kidney disease. The long-term health effects on the heart, lung, and kidney for children and adults undergoing HSCT for cancer have been extensively investigated. These studies provide the best available data to extrapolate the possible late health effects after curative therapy for SCD. Future research is needed to evaluate whether HSCT abates, stabilizes, or exacerbates heart, lung, kidney, and other diseases in children and adults with SCD receiving myeloablative and non-myeloablative conditioning regimens for curative therapy.

Significance of alveolar nitric oxide concentration in the airway of patients with organizing pneumonia after allogeneic hematopoietic stem cell transplantation

Organizing pneumonia (OP) is a complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and a manifestation of peripheral airway/alveolar inflammation. Recently, alveolar nitric oxide concentration (Calv) has been revealed as a noninvasive marker of peripheral airway inflammation; however, whether Calv levels are associated with OP and peripheral airway in patients after allo-HSCT remains unclear. Herein, we evaluated whether Calv levels could reflect the presence of OP and structural airway changes in patients after allo-HSCT. We measured the eNO levels of 38 patients (6 with OP and 32 without OP) who underwent allo-HSCT. Three-dimensional computed tomography (CT) analysis of the airway was performed in 19 patients. We found that in patients with OP, Calv levels were significantly higher than in those without OP (10.6 vs. 5.5 ppb, p < 0.01). Receiver-operating characteristic analyses revealed a Calv cut-off value for OP detection of 10.2 ppb. No significant differences in the patient characteristics, except for the presence of OP (p < 0.01), were noted between the two groups stratified by the Calv cut-off value. Three-dimensional CT images of the airway revealed gradually increasing positive correlations between Calv levels and airway wall area of the third-, fourth-, and fifth-generation bronchi (r = 0.20, 0.31, 0.38; p = 0.42, 0.19, 0.038, respectively), indicating that Calv levels are strongly correlated with the wall thickness of the distal bronchi. Our results suggest that the Calv level may be a useful noninvasive detectable marker for OP after an allo-HSCT.

Characterization of localized macrophages in bronchiolitis obliterans after allogeneic hematopoietic cell transplantation

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) remains one of the most devastating manifestations of chronic graft-versus-host disease in hematopoietic cell transplantation (HCT). Recent findings of BOS after lung transplantation indicate that donor (lung)-derived lung-resident macrophages contribute to BOS, suggesting that differences in the origin of immune cells and localized antigen-presenting cells cause the onset of BOS.

METHODS

We identified the phenotype and origin of infiltrating macrophages using immunohistochemistry and fluorescence in situ hybridization in eight sex-mismatched HCT recipients who underwent lung transplantation for BOS after HCT.

RESULTS

Most of the infiltrating macrophages appeared to be derived from donor (hematopoietic) cells in patients who developed BOS following HCT. Macrophages observed in the early-stage region of BOS were positive for cluster of differentiation (CD)68 and inducible nitric oxide synthase (iNOS) and negative for CD163 and CD206, suggesting an M1 phenotype. In the late-stage region, macrophages were negative for CD68 and iNOS in all patients, but also positive for CD163 and CD206 in some patients.

CONCLUSIONS

Donor-derived M1-macrophages may be involved in the pathogenesis of the early-stage region of BOS. In addition, some macrophages in the late-stage region showed M2 polarization that might be involved in fibrosis.

Pulmonary Complications of Pediatric Hematopoietic Cell Transplantation. A National Institutes of Health Workshop Summary

Approximately 2,500 pediatric hematopoietic cell transplants (HCTs), most of which are allogeneic, are performed annually in the United States for life-threatening malignant and nonmalignant conditions. Although HCT is undertaken with curative intent, post-HCT complications limit successful outcomes, with pulmonary dysfunction representing the leading cause of nonrelapse mortality. To better understand, predict, prevent, and/or treat pulmonary complications after HCT, a multidisciplinary group of 33 experts met in a 2-day National Institutes of Health Workshop to identify knowledge gaps and research strategies most likely to improve outcomes. This summary of Workshop deliberations outlines the consensus focus areas for future research.

Pulmonary surveillance in pediatric hematopoietic stem cell transplant: A multinational multidisciplinary survey

Background

Hematopoietic Stem Cell Transplant (HSCT) is an established treatment for malignant and non‐malignant conditions and pulmonary disease is a leading cause of late term morbidity and mortality. Accurate and early detection of pulmonary complications is a critical step in improving long term outcomes. Existing guidelines for surveillance of pulmonary complications post‐HSCT contain conflicting recommendations.

Aim

To determine the breadth of current practice in monitoring for pulmonary complications of pediatric HSCT.

Methods

An institutional review board approved, online, anonymous multiple‐choice survey was distributed to HSCT and pulmonary physicians from the United States of America and Australasia using the REDcap platform. The survey was developed by members of the American Thoracic Society Working Group on Complications of Childhood Cancer, and was designed to assess patient management and service design.

Results

A total of 40 (34.8%) responses were received. The majority (62.5%) were pulmonologists, and 82.5% were from the United States of America. In all, 67.5% reported having a protocol for monitoring pulmonary complications and 50.0% reported adhering “well” or “very well” to protocols. Pulmonary function tests (PFTs) most commonly involved spirometry and diffusion capacity for carbon monoxide. The frequency of PFTs varied depending on time post‐HSCT and presence of complications. In all, 55.0% reported a set threshold for a clinically significant change in PFT.

Conclusions

These results illustrate current variation in surveillance for pulmonary complications of pediatric HSCT. The results of this survey will inform development of future guidelines for monitoring of pulmonary complications after pediatric HSCT.

Pulmonary Complications in Hematopoietic Stem Cell Transplant Recipients-A Clinician Primer

Hematopoietic stem cell transplants (HSCT) are becoming more widespread as a result of optimization of conditioning regimens and prevention of short-term complications with prophylactic antibiotics and antifungals. However, pulmonary complications post-HSCT remain a leading cause of morbidity and mortality and are a challenge to clinicians in both diagnosis and treatment. This comprehensive review provides a primer for non-pulmonary healthcare providers, synthesizing the current evidence behind common infectious and non-infectious post-transplant pulmonary complications based on time (peri-engraftment, early post-transplantation, and late post-transplantation). Utilizing the combination of timing of presentation, clinical symptoms, histopathology, and radiographic findings should increase rates of early diagnosis, treatment, and prognostication of these severe illness states.

Major pulmonary complications following Hematopoietic stem cell transplantation: What the pulmonologist needs to know

Hematopoietic stem cell transplantation (HSCT) is used for treatment of a myriad of both malignant and non-malignant disorders. However, despite many advances over the years which have resulted in improved patient mortality, this subset of patients remains at risk for a variety of post-transplant complications. Pulmonary complications of HSCT are categorized into infectious and non-infectious and occur in up to one-third of patients undergoing HSCT. Infectious etiologies include bacterial, viral and fungal infections, each of which can have significant mortality if not identified and treated early in the course of infection. Advances in the diagnosis and management of infectious complications highlight the importance of non-infectious pulmonary complications related to chemoradiation toxicities, immunosuppressive drugs toxicities, and graft-versus-host disease. This report aims to serve as a guide and clinical update of pulmonary complications following HSCT for the general pulmonologist who may be involved in the care of these patients.

Pulmonary Manifestations of Hematologic and Oncologic Diseases in Children

Pulmonary complications are common in children with hematologic or oncologic diseases, and many experience long-term effects even after the primary disease has been cured. This article reviews pulmonary complications in children with cancer, after hematopoietic stem cell transplant, and caused by sickle cell disease and discusses their management.

[Fibrotic remodeling of the lung following lung and stem-cell transplantation]

Transplantation of solid organs and hematopoietic stem cells represents an important therapeutic option for a variety of end-stage pulmonary diseases, aggressive hematopoietic neoplasms, or severe immunodeficiencies. Although the overall survival following transplantation has generally improved over recent decades, long-time survival of lung and stem-cell transplant recipients is still alarmingly low with an average 5‑year survival rate of only 50-60%. Chronic allo-immunoreactions in general and pulmonary allo-immunoreactions with subsequent fibrosis in particular are major reasons for this poor outcome. Comparable patterns of fibrotic lung remodeling are observed following both lung and hematopoietic stem-cell transplantation. Besides the meanwhile well-established obliterative and functionally obstructive remodeling of the small airways - obliterative bronchiolitis - a specific restrictive subform of fibrosis, namely alveolar fibroelastosis, has been identified. Despite their crucial impact on patient outcome, both entities can be very challenging to detect by conventional histopathological analysis. Their underlying mechanisms are considered overreaching aberrant repair attempts to acute lung injuries with overactivation of (myo-) fibroblasts and excessive and irreversible deposition of extracellular matrix. Of note, the underlying molecular mechanisms are widely divergent between these two morphological entities and are independent of the underlying clinical setting.Further comprehensive investigations of these fibrotic alterations are key to the development of much-needed predictive diagnostics and curative concepts, considering the high mortality of pulmonary fibrosis following transplantation.

Transplant characteristics and self-reported pulmonary outcomes in Swiss childhood cancer survivors after hematopoietic stem cell transplantation-a cohort study

Childhood cancer survivors treated with hematopoietic stem cell transplantation are at high risk for pulmonary morbidity and mortality. In this retrospective study we described transplant characteristics of pediatric patients who underwent hematopoietic stem cell transplantation in Switzerland and how these characteristics changed over time, compared self-reported pulmonary outcomes between transplanted and non-transplanted survivors, and investigated risk factors for the reported pulmonary outcomes. As part of the population-based Swiss Childhood Cancer Survivor Study, we sent questionnaires to all ≥5-year childhood cancer survivors diagnosed 1976–2010 at age ≤20 years. We included 132 transplanted survivors and 368 matched non-transplanted survivors. During the study period transplant characteristics changed, with decreasing use of total body irradiation and increased use of peripheral blood stem cells and mismatched and unrelated donors as transplant source. One-fifth of transplanted survivors (20%, 95%CI 13–27%) and 18% of non-transplanted survivors (95%CI 13–21%) reported at least one pulmonary outcome. None of the analyzed factors was significantly associated with an increased risk of pulmonary outcomes in multivariable analysis. We found that pulmonary outcomes were frequently reported in transplanted and non-transplanted childhood cancer survivors, indicating a strong need for long-term pulmonary follow-up care.

Long-term Follow-up of Hematopoietic Stem Cell Transplant Survivors: A Focus on Screening, Monitoring, and Therapeutics

Annually, ~50,000 patients undergo hematopoietic stem cell transplantation (HCT) worldwide with almost 22,000 of these patients receiving HCT in the United States. HCT is a curative option for a wide range of hematologic malignancies, and advances in transplantation medicine have resulted in an increase in HCT survivors. It is anticipated that the number of HCT survivors will more than double from 242,000 in 2020 to ~500,000 in 2030. Survivors of HCT are at an increased risk of developing late complications due to exposure to chemotherapy and/or radiation in the pre-, peri-, and post-HCT phases and these cumulative exposures have the potential to damage normal tissue. This tissue damage leads to the early onset of chronic health conditions resulting in premature mortality in HCT survivors, who have a 15-year cumulative incidence of severe or life-threatening chronic health conditions exceeding 40%. Due to the significant burden of morbidity in HCT survivors and the delay in the development of long-term complications, this delicate patient population requires life-long monitoring due to the risk for neuropsychological, cardiac, pulmonary, renal, hepatic, ocular, skeletal, cardiac, endocrine, fertility, and sexual health complications, as well as secondary neoplasms. This review will focus on recent advances in screening, monitoring, and therapeutics for late-occurring or long-term complications in HCT survivors.

Noninfectious pulmonary complications of haematopoietic stem cell transplantation

Haematopoietic stem cell transplantation (HSCT) is an established treatment for a variety of malignant and nonmalignant conditions. Pulmonary complications, both infectious and noninfectious, are a major cause of morbidity and mortality in patients who undergo HSCT. Recent advances in prophylaxis and treatment of infectious complications has increased the significance of noninfectious pulmonary conditions. Acute lung injury associated with idiopathic pneumonia syndrome remains a major acute complication with high morbidity and mortality. On the other hand, bronchiolitis obliterans syndrome is the most challenging chronic pulmonary complication facing clinicians who are taking care of allogeneic HSCT recipients. Other noninfectious pulmonary complications following HSCT are less frequent. This review provides a clinical update of the incidence, risk factors, pathogenesis, clinical characteristics and management of the main noninfectious pulmonary complications following HSCT.

Noninfectious pulmonary complications following haematopoietic stem cell transplantation is a major cause of morbidity and mortality in this patient population. There are recent advances in the diagnosis and management of these conditions.http://bit.ly/2FgsIYG

Optimal Delivery of Follow-Up Care After Allogeneic Hematopoietic Stem-Cell Transplant: Improving Patient Outcomes with a Multidisciplinary Approach

The increasing indications for allogeneic stem-cell transplant in patients with hematologic malignancies and non-malignant diseases combined with improved clinical outcomes have contributed to increase the number of long-term survivors. However, survivors are at increased risk of developing a unique set of complications and late effects, besides graft-versus-host disease and disease relapse. In this setting, the management capacity of a single health-care provider can easily be overwhelmed. Thus, to provide appropriate survivorship care, a multidisciplinary approach for the long-term follow-up is essential. This review aims at summarizing the most relevant information that a health-care provider should know to establish a follow-up care plan, in the light of individual exposures and risk factors, that includes all organ systems and considers the psychological burden of these patients.

Late Noninfectious Pulmonary Complications in Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic modality for a number of malignant and nonmalignant conditions. Pulmonary complications following HSCT are associated with increased mortality and morbidity. These complications may be classified into infectious versus noninfectious, and early versus late based on the time of occurrence post-transplant. Thus, exclusion of infectious etiologies is the first step in the diagnoses of pulmonary complications. Late onset noninfectious pulmonary complications typically occur 3 months post-transplant. Bronchiolitis obliterans is the major contributor to late-onset pulmonary complications, and its clinical presentation, pathogenesis, and current therapeutic approaches are discussed. Idiopathic pneumonia syndrome is another important complication which usually occurs early, although its onset may be delayed. Organizing pneumonia is important to recognize due to its responsiveness to corticosteroids. Other late onset noninfectious pulmonary complications discussed here include pulmonary venoocclusive disease, pulmonary cytolytic thrombi, pleuroparenchymal fibroelastosis, thoracic air leak syndrome, and posttransplant lymphoproliferative disorders.

Organizing pneumonia secondary to Pneumocystis jirovecii infection in a kidney transplant recipient: Case report and review of literature

Organizing pneumonia (OP), previously known as bronchiolitis obliterans OP, is a diffuse parenchymal lung disease affecting the distal bronchioles, alveolar ducts, and alveolar walls. Pulmonary infections, especially bacterial and viral diseases, are known to be associated with the secondary form of OP. OP secondary to fungal infections is less common. Here, we report a case of OP associated with pneumocystis pneumonia (PCP) in a kidney transplant recipient on tacrolimus-based triple immunosuppression. The index case had developed new lung consolidation toward the end of trimethoprim-sulfamethoxazole therapy for PCP. Spontaneous clinical and radiographic resolution was seen without any increment in the dose of corticosteroids. We review the literature and present a summary of all reported cases of OP associated with PCP to date.

Monitoring lung function in patients with chronic graft versus host disease: a pilot study

Bronchiolitis obliterans syndrome (BOS) following allogenic haematopoietic stem cell transplant is considered the manifestation of chronic graft versus host disease (cGvHD) in the lung, and affects about 14% of patients with cGvHD, mainly in the first 2 years after transplant. Despite advances in assessment, diagnosis and treatment, the clinical prognosis remains poor for patients with pulmonary manifestations of cGvHD. A pilot study of 50 patients was devised to establish whether a relationship exists between forced expiratory volume in 1 second (FEV1) via pulmonary function test (PFT) and the equivalent peak expiratory flow (PEF) via peak flow handheld spirometry in cGvHD patients receiving extracorporeal photopheresis (ECP). Only PEF observed within 2 days of PFT could be compared with data at month 3, 6, 9 and 12. This pilot study illustrated that monitoring via handheld peak flow readings has the potential to become an acceptable method of monitoring lung function longitudinally in cGvHD patients.

Incidence, Risk Factors, and Outcomes of Idiopathic Pneumonia Syndrome after Allogeneic Hematopoietic Cell Transplantation

Our current knowledge of idiopathic pneumonia syndrome (IPS) predates improved specificity in the diagnosis of IPS and advances in hematopoietic cell transplantation (HCT) and critical care practices. In this study, we describe and update the incidence, risk factors, and outcomes of IPS. We performed a retrospective cohort study of all adults who underwent allogeneic HCT at the Fred Hutchinson Cancer Research Center between 2006 and 2013 (n = 1829). IPS was defined using the National Heart, Lung, and Blood Institute consensus definition: multilobar airspace opacities on chest imaging, absence of lower respiratory tract infection, and hypoxemia. We described IPS incidence and mortality within 120 and 365 days after HCT. We examined conditioning intensity (nonmyeloablative versus myeloablative with high-dose total body irradiation [TBI] versus myeloablative with low-dose TBI) as an IPS risk factor in a time-to-event analysis using Cox models, controlled for age at transplant, HLA matching, stem cell source, and pretransplant Lung function Score (a combined measure of impairment in Forced Expiratory Volume in the first second (FEV₁) and Diffusion capacity for carbon monoxide (DLCO)). Among 1829 HCT recipients, 67 fulfilled IPS criteria within 120 days (3.7%). Individuals who developed IPS were more likely to be black/non-Hispanic versus other racial groups and have severe pulmonary impairment but were otherwise similar to participants without IPS. In adjusted models, myeloablative conditioning with high-dose TBI was associated with increased risk of IPS (hazard ratio, 2.5; 95% confidence interval, 1.2 to 5.2). Thirty-one patients (46.3%) with IPS died within the first 120 days of HCT and 47 patients (70.1%) died within 365 days of HCT. In contrast, among the 1762 patients who did not acquire IPS in the first 120 days, 204 (11.6%) died within 120 days of HCT and 510 (29.9%) died within 365 days of HCT. Our findings suggest that although the incidence of IPS may be declining, it remains associated with post-transplant mortality. Future study should focus on early detection and identifying pathologic mediators of IPS to facilitate timely, targeted therapies for those most susceptible to lung injury post-HCT.

Bronchoscopic features, associations, and outcomes of organizing pneumonia following allogeneic hematopoietic stem cell transplantation

Organizing pneumonia (OP) is a poorly understood complication of hematopoietic stem cell transplant (HSCT). We identified 15 patients diagnosed with OP following HSCT and described their clinical course. CT chest findings were remarkable for multifocal infiltrates that were predominantly consolidating or ground glass opacities. Bronchoalveolar lavage (BAL) was performed on 14 patients with five having lymphocytosis (> 25% lymphocytes), three with eosinophilia (> 5% eosinophils), three with neutrophilia (> 30% neutrophils), and three with normal cell counts. Flow cytometry was analyzed on BAL fluid in 13 patients with 11 having a CD4/CD8 of < 0.9. Initial treatment with 0.3–1.0 mg/kg prednisone resulted in improvement in symptoms, in radiographic findings, and in pulmonary function testing for the majority of patients. Six patients had recurrence of OP after completing treatment. Eleven patients had evidence of extra-pulmonary graft-versus-host disease prior to diagnosis of OP, and seven patients were diagnosed with an upper respiratory tract infection (URI) within 8 weeks of OP diagnosis. Most patients respond well to prednisone with significant improvement in pulmonary function, but risk of recurrence is high after cessation of steroid treatment. Risk factors for the development of OP may include prior URI.

An Analysis of the Clinical Benefit of 37 Bronchoalveolar Lavage Procedures in Patients with Hematologic Disease and Pulmonary Complications

Objective Since pulmonary complications are a major cause of mortality in patients with hematologic diseases, their rapid detection and treatment are essential. Bronchoalveolar lavage (BAL) is widely performed to diagnose pulmonary infiltrates not evident with non-invasive investigations; however, reports on its clinical benefits for patients with hematologic diseases are limited. The aim of our study was to investigate the utility of diagnostic bronchoscopy with BAL for those patients. Methods We retrospectively reviewed the clinical records of 37 consecutive BAL procedures in 33 adult patients with hematological diseases and pulmonary infiltrates with at least 6 months of follow-up between August 2013 and September 2017 (total 747 BAL procedures). The BAL results, ensuing treatment modifications, treatment outcomes, survival times, and adverse events were evaluated. Results Microbiological findings were detected in 11 (29.7%), even though wide-spectrum antibiotics and antifungal drugs had been empirically administered to most patients (>70%) prior to the bronchoscopy procedure. Overall, 25 of the 37 BAL procedures (67.6%) had some impact on the diagnosis of pulmonary diseases. Patients without specific diagnostic findings from BAL had a significantly poorer survival than those with diagnostic findings via BAL (30-day survival: 33.3% vs. 92.0%; 180-day survival: 8.3% vs. 64.0%). Four patients (12.1%) experienced complications associated with bronchoscopy; there were no procedure-related deaths. Conclusion BAL seems still important for diagnosing pulmonary infiltrates and/or excluding some of the important respiratory tract pathogens in patients with hematological diseases; furthermore, negative specific diagnostic findings from BAL may be associated with poor prognoses.

Patterns of onset and outcome of cryptogenic organizing pneumonia after allogeneic hematopoietic stem cell transplantation

Cryptogenic organizing pneumonia (COP) after allogeneic hematopoietic stem cell transplantation (HSCT) is characterized by frequent recurrence. Few studies have examined onset and recurrence patterns of COP after HSCT. We investigated the clinical features of COP after HSCT in a single-center retrospective study including 165 consecutive patients who underwent allogeneic HSCT. Eighteen patients (11%) developed COP after HSCT. Hypoxemia and pleural effusion at the onset of COP were significantly associated with umbilical cord blood transplantation (P = 0.002 and P = 0.002, respectively). Recurrence of COP was observed in six patients and significantly associated with the presence of chronic graft-versus-host disease (cGVHD; P = 0.013) and stem cell sources other than umbilical cord blood (P = 0.038). Four patients with COP died of pulmonary failure after recurrence of COP. No patients who underwent umbilical cord blood transplantation experienced recurrence of COP. These findings suggest that the clinical features at the onset of COP may depend on stem cell sources. Moreover, both stem cell source and the absence or presence of cGVHD may affect COP recurrence, indicating the need to develop treatment strategies against COP according to stem cell source and risk of cGVHD.

Complications of Stem Cell Transplantation that Affect Infections in Stem Cell Transplant Recipients, with Analogies to Patients with Hematologic Malignancies

This article discusses the complications of hematopoietic stem cell transplantion (HSCT) that affect infections in HSCT recipients, with analogies to patients with hematologic malignancies. Mucositis, with mucosal barrier disruption, is common and increases the risk of gram-positive and anaerobic bacterial, and fungal infections, and can evolve to typhlitis. Engraftment syndrome; graft-versus-host disease, hepatic sinusoidal obstruction syndrome; and posterior reversible encephalopathy syndrome can affect the infectious potential either directly from organ dysfunction or indirectly from specific treatment. Pulmonary infections can predispose to life threatening complications including diffuse alveolar hemorrhage, idiopathic pulmonary syndrome, bronchiolitis obliterans syndrome, and bronchiolitis obliterans with organizing pneumonia.

High probability of follow-up termination among AYA survivors after allogeneic hematopoietic cell transplantation

The need for long-term follow-up (LTFU) after allogeneic hematopoietic cell transplantation (HCT) has been increasingly recognized for managing late effects such as subsequent cancers and cardiovascular events. A substantial population, however, has already terminated LTFU at HCT centers. To better characterize follow-up termination, we analyzed the Japanese transplant registry database. The study cohort included 17 980 survivors beyond 2 years who underwent their first allogeneic HCT between 1974 and 2013. The median patient age at HCT was 34 years (range, 0-76 years). Follow-up at their HCT center was terminated in 4987 patients. The cumulative incidence of follow-up termination was 28% (95% confidence interval [CI], 27%-29%) at 10 years, increasing to 67% (95% CI, 65%-69%) at 25 years after HCT. Pediatric patients showed the lowest probability of follow-up termination for up to 16 years after HCT, whereas adolescent and young adult (AYA) patients showed the highest probability of follow-up termination throughout the period. Follow-up termination was most often made by physicians based on the patient's good physical condition. Multivariate analysis identified 6 factors associated with follow-up termination: AYA patients, female patients, standard-risk malignancy or nonmalignant disease, unrelated bone marrow transplantation, HCT between 2000 and 2005, and absence of chronic graft-versus-host disease. These results suggest the need for education of both physicians and patients about the importance of LTFU, even in survivors with good physical condition. The decreased risk for follow-up termination after 2005 may suggest the increasing focus on LTFU in recent years.

Combination of pleuroparenchymal fibroelastosis with non-specific interstitial pneumonia and bronchiolitis obliterans as a complication of hematopoietic stem cell transplantation - Clues to a potential mechanism

Pleuroparenchymal fibroelastosis (PPFE) is a newly described entity of interstitial lung disease, which has been recently recognized as a rare complication of bone marrow transplantation. We report a case of 30-year-old man who developed a unique combination of pleuroparenchymal fibroelastosis with cellular and fibrotic non-specific interstitial pneumonia (NSIP) and bronchiolitis obliterans (BO) sixteen years after hematopoietic stem cell transplantation. Histological examination revealed almost exclusive infiltration of CD3-positive T lymphocytes associated with lymphoepithelial lesions and multi-focal denudation of covering epithelial cells in all components. This case suggests PPFE, NSIP, and BO might be conditions of the same spectrum, pathogenetically related to chronic graft-versus-host disease. Immunostaining for CD3 and CD20 in transbronchial lung biopsies may be helpful for identifying graft-versus-host-driven interstitial lung disease.

Decline of forced expiratory volume in 1 s after allogeneic hematopoietic cell transplantation is a good indicator for pulmonary damage and is associated with busulfan use

Reduced pulmonary function is commonly observed after allogeneic hematopoietic stem cell transplantation (HSCT); however, its relationship with the development of noninfectious pulmonary complications (NIPCs) is unclear, and the impact of changes in pulmonary function test (PFT) values on HSCT outcome remains controversial. We conducted a retrospective study including 150 patients to investigate changes in PFTs and impact on clinical outcome. PFT data at around 1 year after HSCT were available in 84 patients, and showed a significant time-dependent decline in percentage predicted forced expiratory volume in 1 s and other parameters. We focused on %FEV1, calculated decline of %FEV1 from pretransplant to around 1 year after HSCT (Δ%FEV1), and divided patients into good-Δ%FEV1 or poor-Δ%FEV1 groups, using a cut-off point of 20% decline of Δ%FEV1. In the poor-Δ%FEV1 group, half of the patients developed NIPCs. In the good-Δ%FEV1 group, PFT values were maintained, whereas those of the poor-Δ%FEV1 group declined significantly. Multivariate analysis showed that busulfan use was a risk factor for %FEV1 decline, and poor-Δ%FEV1 was a risk factor for overall survival. These data indicate that decline of %FEV1 may be a useful indicator of pulmonary damage after HSCT, and is strongly associated with busulfan use.

Current Approach to Non-Infectious Pulmonary Complications of Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation is an established treatment for patients with a wide range of malignant and nonmalignant conditions. Noninfectious pulmonary complications still remain a leading cause of morbidity and mortality in these patients. Treating hematopoietic stem cell transplantation recipients with noninfectious pulmonary complications is still challenging, and the current treatment armamentarium and strategies are not adequate for patients receiving hematopoietic stem cell transplantation. Further trials are needed for a better description of the pathogenesis and the complete diagnostic criteria as well as for the development of effective therapeutic approaches for the management of noninfectious pulmonary complications of the hematopoietic stem cell transplantation. This review outlines the incidence, risk factors, pathogenesis, and clinical spectrum and discusses the current approaches to the management of noninfectious pulmonary complications of Hematopoietic stem cell transplantation.

Lung Dysbiosis, Inflammation, and Injury in Hematopoietic Cell Transplantation

RATIONALE

Hematopoietic cell transplant (HCT) is a common treatment for hematological neoplasms and autoimmune disorders. Among HCT recipients, pulmonary complications are common, morbid, and/or lethal, and they have recently been associated with gut dysbiosis. The role of lung microbiota in post-HCT pulmonary complications is unknown.

OBJECTIVES

To investigate the role of lung microbiota in post-HCT pulmonary complications using animal modeling and human BAL fluid.

METHODS

For animal modeling, we used an established murine model of HCT with and without postengraftment herpes virus infection. For human studies, we characterized lung microbiota in BAL fluid from 43 HCT recipients. Lung bacteria were characterized using 16S ribosomal RNA gene sequencing and were compared with lung histology (murine) and with alveolar inflammation and pulmonary function testing (human).

MEASUREMENTS AND MAIN RESULTS

Both HCT and viral infection independently altered the composition of murine lung microbiota, but they had no effect on lung microbial diversity. By contrast, combined HCT and viral infection profoundly altered lung microbiota, decreasing community diversity with an associated pneumonitis. Among human HCT recipients, increased relative abundance of the Proteobacteria phylum was associated with impaired pulmonary function, and lung microbiota were significantly associated with alveolar concentrations of inflammatory cytokines.

CONCLUSIONS

In animal models and human subjects, lung dysbiosis is a prominent feature of HCT. Lung dysbiosis is correlated with histologic, immunologic, and physiologic features of post-HCT pulmonary complications. Our findings suggest the lung microbiome may be an unappreciated target for the prevention and treatment of post-HCT pulmonary complications.

Respiratory failure in the hematopoietic stem cell transplant recipient

The number of patients receiving hematopoietic stem cell transplantation (HSCT) is rapidly rising worldwide. Despite substantial improvements in peri-transplant care, pulmonary complications resulting in respiratory failure remain a major contributor to morbidity and mortality in the post-transplant period, and represent a major barrier to the overall success of HSCT. Infectious complications include pneumonia due to bacteria, viruses, and fungi, and most commonly occur during neutropenia in the early post-transplant period. Non-infectious complications include idiopathic pneumonia syndrome, peri-engraftment respiratory distress syndrome, diffuse alveolar hemorrhage, pulmonary veno-occlusive disease, delayed pulmonary toxicity syndrome, cryptogenic organizing pneumonia, bronchiolitis obliterans syndrome, and post-transplant lymphoproliferative disorder. These complications have distinct clinical features and risk factors, occur at differing times following transplant, and contribute to morbidity and mortality.

Influence of Total Body Irradiation Dose Rate on Idiopathic Pneumonia Syndrome in Acute Leukemia Patients Undergoing Allogeneic Hematopoietic Cell Transplantation

PURPOSE

To determine the relationship between dose rate and other factors in the development of idiopathic pneumonia syndrome (IPS) in patients with acute lymphoblastic leukemia or acute myeloid leukemia who are undergoing total body irradiation (TBI)-based myeloablative conditioning for allogeneic hematopoietic cell transplantation (HCT).

METHODS AND MATERIALS

From 2006 to 2016, 202 patients with acute leukemia (111 acute lymphoblastic leukemia, 91 acute myeloid leukemia) ranging in age from 1 to 57 years (median, 25 years) underwent allogeneic HCT at University of Minnesota. Pretransplantation conditioning included cyclophosphamide (120 mg/kg) with (68%) or without fludarabine (75 mg/m²) followed by 13.2 Gy TBI given in 8 twice-daily fractions of 1.65 Gy over 4 days. Dose rate varied based on linear accelerator availability and ranged from 8.7 to 19.2 cGy/min. Patients were stratified by receipt of high-dose-rate (HDR; >15 cGy/min; 56%) or low-dose-rate (LDR; ≤15 cGy/min; 44%) TBI for all 8 fractions. IPS was defined as pulmonary injury based on clinical symptoms, radiographic evidence, or pulmonary function testing within 100 days of HCT in the absence of concurrent infection.

RESULTS

IPS developed in 42 patients (21%) between 4 and 73 days (median, 16 days) after transplantation. HDR TBI was associated with a higher rate of IPS compared with LDR TBI (29% vs 10%; P < .01). On multiple regression analysis, HDR remained a significant predictor of IPS (hazard ratio, 2.6; 95% confidence interval, 1.2-5.3; P = .01), and this led to inferior 1-year overall survival (60% vs 76%; P = .01) and increased 1-year nonrelapse mortality (28% vs 15%; P = .02).

CONCLUSIONS

TBI dose rates ≤15 cGy/min reduce the risk of posttransplantation IPS and improve overall survival. LDR TBI should be strongly considered as an easily implemented parameter to improve the safety of pretransplantation TBI-based conditioning.

High-Resolution CT Findings of Obstructive and Restrictive Phenotypes of Chronic Lung Allograft Dysfunction: More Than Just Bronchiolitis Obliterans Syndrome

OBJECTIVE

The purpose of this article is to review the high-resolution CT characteristics of individual obstructive and restrictive chronic lung allograft dysfunction (CLAD) phenotypes to aid in making accurate diagnoses and guiding treatment.

CONCLUSION

Long-term survival and function after lung transplant are considerably worse compared with after other organ transplants. CLAD is implicated as a major limiting factor for long-term graft viability. Historically thought to be a single entity, bronchiolitis obliterans syndrome, CLAD is actually a heterogeneous group of disorders with distinct subtypes.

Bone marrow transplant-induced alterations in Notch signaling promote pathologic Th17 responses to γ-herpesvirus infection

Idiopathic pneumonia syndrome (IPS) is a common, often fatal, complication following hematopoietic stem cell transplantation (HSCT) characterized by severe pneumonitis and interstitial fibrosis. Fully reconstituted syngeneic bone marrow transplant (BMT) mice infected with murine γ-herpesvirus-68 develop interleukin-17 (IL-17)-driven pneumonitis and fibrosis, which mimics clinical manifestations of IPS. We found CD103+ and CD11b+ dendritic cells (DCs) are selectively deficient for the Notch ligand, DLL4, following BMT and CD4+ T cells isolated from lungs and spleens of infected BMT mice display Notch signaling defects. Mice transplanted with CD4-Cre-driven dominant-negative Notch transcriptional regulator Mastermind-Like (CD4-Cre-DNMAML (CCD) mice) bone marrow displayed elevated IL-17 and transforming growth factor-β (TGF β) in the lungs, a further expansion of T-helper type 17 (Th17) cells, and developed more fibrosis than wild-type (WT)-BMT mice. Culture of BMT lung leukocytes with recombinant Notch ligand, DLL4, restored Notch signaling and decreased production of IL-17. Adoptive transfer of CD11c+ DCs could restore Th1 and limit Th17 in WT-BMT but not CCD-BMT mice, indicating that a specific DC/CD4+ T-cell Notch interaction modulates IL-17 production following reconstitution in syngeneic BMT mice. Given recent clinical observations showing that patients with pulmonary complications post-transplant harbor occult herpesvirus infections, these data provide mechanistic insight and suggest potential therapies for these devastating conditions.

Results of quantitative chest-CT in chronic pulmonary graft-vs.-host disease (cGvHD) 3 years after allogeneic stem cell transplantation

BACKGROUND

To quantify lung parenchymal changes in symptomatic patients with chronic pulmonary graft-versus-host disease 3 years after allogeneic stem cell transplantation (allo-SCT) by means of CT-densitometry (CTD) and to compare results with those of established pulmonary function tests (PFT).

METHODS

The study group consisted of 26 patients with pulmonary cGvHD (19 males, 7 females; mean age, 49.29±15.89; range, 19-72 years). The diagnosis was based on clinical symptoms, PFT and chest-CT findings. CTD and PFT were performed both in the pre- and post-transplantation setting and results compared with each other. CT scans were obtained during suspended deep inspiration including the whole lungs. The mean lung attenuation (MLD), low attenuation values (LAV) and distribution of focal parenchymal abnormalities compatible with emphysema (HU <-950) were quantitatively calculated with histograms and graphics. On PFT, total lung capacity (TLC), residual volume (RV), vital capacity (VC), forced expiratory volume in 1 s (FEV1s) and diffusion capacity for carbon monoxide (DLCOSB) were registered.

RESULTS

Changes in end-inspiratory lung volume and density (MLD and LAV) in symptomatic cGvHD patients in mean three years after allo-SCT proved all not significant, but there was a clear trend towards an increase in lung volume and a decrease in lung attenuation. These results were similar throughout all classes of bronchiolitis obliterans (BO) by cGvHD. PFT showed a significant decrease in VC, FEV1s but only a minimal decrease in DLCOSB. Changes in FVC after stem cell transplantation correlated with changes in LAV (r=0.649, P=0.031). Predicted VC correlated with changes in LAV (r=0.771, P=0.005). There was a correlation between the absolute difference of FEV1 and DLCOSB (r=0.64, P=0.14) before and after stem cell transplantation.

CONCLUSIONS

End-inspiratory phase CT lung parenchyma quantification in symptomatic patients with pulmonary cGvHD 3 years after allo-SCT shows discrete changes over the pre-transplantation setting representing airway obstruction, mirroring airflow limitation on PFT. Its use enables exclusion of relevant parenchymal destruction (emphysema-equivalent lung density) at this time.

Computed Tomographic Appearance of Organizing Pneumonia in an Oncologic Patient Population

OBJECTIVE

The aims of this study were to describe the computed tomographic features of organizing pneumonia (OP) in an oncologic patient population and to also identify features associated with lung cancer and patients undergoing hematopoietic stem cell transplant (HSCT).

METHODS

In retrospective computed tomographies from 151 patients with pathologically confirmed OP between January 2009 and September 2014, number of lesions, location, size, margin type, and consistency, as well as volume of lymphadenopathy and the presence and size of pleural effusions, were recorded. Associated malignancy was noted.

RESULTS

Organizing pneumonia most commonly presented as a diffuse process (n = 62, 41%), frequently occupied both a central and peripheral location (n = 79, 53%), and commonly presented with a solid appearance (n = 67, 44%) or with ground glass opacity (n = 80, 53%). Pleural effusions were seen in 68 patients (45%). Organizing pneumonia less frequently contained air bronchograms, cavitation, necrosis, surrounding ground glass opacity, or adjacent bronchiectasis. In patients with lung cancer (n = 25, 17%), OP more likely presented as discrete lesions and occupied a peripheral location as compared with patients with other malignancies (Ps = 0.025 and 0.002). In HSCT patients (n = 29, 19%), a diffuse process was more commonly seen than in non-HSCT patients (P = 0.038).

CONCLUSIONS

Organizing pneumonia more commonly presents as discrete lesions with a peripheral location in patients with lung cancer and as a diffuse process in patients who had undergone HSCT.

Pulmonary Clinicopathological Correlation after Allogeneic Hematopoietic Stem Cell Transplantation: An Autopsy Series

Pulmonary complications are a significant cause of morbidity, mortality, and resource utilization after hematopoietic stem cell transplantation (HSCT). The objective of this study was to compare antemortem clinical suspicion of pulmonary complications and postmortem findings in a modern HSCT cohort. All patients who underwent allogeneic HSCT at our institution (n = 1854) between January 1, 2000 and June 30, 2010 were reviewed and patients who died of any cause greater than 1 year after HSCT and had an unrestricted autopsy available for analysis were included. Presence of pulmonary graft-versus-host disease (GVHD) was assessed by a pathologist blinded to the autopsy report, as previously described by Yousem (1995). A total of 35 (1.9%) patients had autopsies available for review. Airway disease, vascular disease, and interstitial disease were all clinically under-recognized compared with the pathological findings on autopsy. Varying degrees of pathological changes were detected, including 10 (28.6%) patients having bronchiolitis obliterans (BO) and 12 (34.3%) patients having pulmonary veno-occlusive disease (PVOD). Pulmonary manifestations of chronic GVHD, particularly BO and PVOD, were clinically under-recognized in our cohort. Our results suggest that PVOD, which has traditionally been considered a rare complication, may be clinically and histologically under-recognized.

The Biology of Chronic Graft-versus-Host Disease: A Task Force Report from the National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease

Chronic graft-versus-host disease (GVHD) is the leading cause of late, nonrelapse mortality and disability in allogeneic hematopoietic cell transplantation recipients and a major obstacle to improving outcomes. The biology of chronic GVHD remains enigmatic, but understanding the underpinnings of the immunologic mechanisms responsible for the initiation and progression of disease is fundamental to developing effective prevention and treatment strategies. The goals of this task force review are as follows: This document is intended as a review of our understanding of chronic GVHD biology and therapies resulting from preclinical studies, and as a platform for developing innovative clinical strategies to prevent and treat chronic GVHD.